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Background: Hyperexcitability of hippocampal CA1 pyramidal neurons contributes to cognitive deficits in Alzheimer's disease (AD). Tropisetron, a 5-HT receptor antagonist and partial α7 nicotinic acetylcholine receptor (α7nAChR) agonist, has shown neuroprotective effects, but its impact on hippocampal neuronal excitability remains unclear.
Objective: This study aimed to examine the effects of tropisetron on CA1 pyramidal neurons and fast-spiking interneurons in wild-type (WT) and hAPP-J20 AD model mice, a transgenic model for early-onset AD.
Methods: Whole-cell patch-clamp recordings were performed on hippocampal slices from 4-month-old WT and hAPP-J20 mice. Neuronal firing and action potential characteristics, including resting membrane potential (RMP), input resistance, threshold, amplitude and half-width were assessed with and without tropisetron.
Results: Pyramidal neurons in hAPP-J20 mice exhibited hyperexcitability, characterized by enhanced spike numbers, increased input resistance, and decreased RMP. Tropisetron significantly decreased their excitability accompanied by lowering action potential threshold and reducing amplitude. In contrast, tropisetron induced complex effects on fast-spiking interneurons, including a reduction in spike numbers at higher current steps, a lower action potential threshold, and a decrease in spike amplitude.
Conclusion: Tropisetron modulates the firing activity of pyramidal and fast-spiking hippocampal CA1 neurons in hAPP-J20 mice, suggesting its potential to restore network balance and mitigate AD-related dysfunctions. These findings support further investigation into tropisetron as a therapeutic agent for AD.
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http://dx.doi.org/10.1016/j.neulet.2025.138360 | DOI Listing |
EMBO J
September 2025
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
During a critical period of postnatal brain development, neural circuits undergo significant refinement coincident with widespread alternative splicing of hundreds of genes, which undergo altered splice site selection for the generation of isoforms essential for synaptic plasticity. Here, we reveal that neuronal activity-dependent phosphorylation of paxillin at its serine 119 (p-paxillin) acts as a molecular switch in the nucleus for the control of alternative splicing during this period. We show that following NMDA receptor activation, nuclear p-paxillin is recruited to nuclear speckles, where it interacts with splicing factors, such as U2AFs.
View Article and Find Full Text PDFPharmacol Biochem Behav
September 2025
Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Universidad de Málaga (UMA), Málaga, 29010, Spain; Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina (IBIMA Plataforma BIONAND), Málaga, Spain. Electronic address:
Adolescence is a period of heightened neuroplasticity and vulnerability to environmental insults, including drug exposure. In this study, we investigated the short- and long-term behavioral effects, as well as the long-term hippocampal effects, of chronic cocaine administration during adolescence, along with the potential neuroprotective role of insulin-like growth factor 2 (IGF2) in male C57BL/6J mice. Over 21 days, mice received daily intraperitoneal injections of saline, cocaine, IGF2, or a combination of cocaine and IGF2.
View Article and Find Full Text PDFAsian J Psychiatr
September 2025
National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China; Rehabilitation Industry Institute, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China; Traditional Chinese Medicine Re
Background: Amnestic mild cognitive impairment (aMCI) is characterized by marked episodic memory decline. The hippocampus is essential for episodic memory, and integration of information within its subregions is central to this process. This study examined how alterations in hippocampal subregional network relate to episodic memory impairment in aMCI.
View Article and Find Full Text PDFJ Neurophysiol
September 2025
Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT, USA.
Although glutamatergic and GABAergic synapses are important in seizure generation, the contribution of non-synaptic ionic and electrical mechanisms to synchronization of seizure-prone hippocampal neurons remains unclear. Here, we developed a physiologically relevant model to study these mechanisms by inducing prolonged seizure-like discharges (SLDs) in hippocampal slices from male rats through modest, sustained ionic manipulations. Specifically, we reduced extracellular calcium to 0.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Institut de Biologie de l'Ecole Normale Supérieure, Ecole Normale Supérieure, Université Paris Sciences et Lettres, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Paris 75005, France.
Excitatory glycine receptors (eGlyRs), composed of the glycine-binding NMDA receptor subunits GluN1 and GluN3A, have recently emerged as a novel neuronal signaling modality that challenges the traditional view of glycine as an inhibitory neurotransmitter. Unlike conventional GluN1/GluN2 NMDARs, the distribution and role of eGlyRs remain poorly understood. Here, we show that eGlyRs are highly enriched in the ventral hippocampus (VH) and confer distinct properties on this brain region.
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